Mr. Norman has good information.
I have little problem with people using these things as long as they are honest with themselves (and others) and admit they have something that isn't PC/HC. On the other hand, when presenting to the public, we need to be as correct as possible based upon the information we have. That isn't to say that we will be 100%, but be as close as possible. Personally, I carry a jackware canteen, but share that people of the day wouldn't have really carried a canteen (unless military), but modern needs for clean water make it necessary. Also, jackware was somewhat out of fashion in the 1700s and the example my canteen is inspired by is from the 1500's wreck of the Mary Rose and Rundlets. It is functional, light, tough, made from period materials but not necessarily PC.
A salt container of some sort is a handy thing, so using something that is PC/HC, even if used in an unconventional manner, is better than making something up.
And yes, clothing laced with large X-shaped stitches is something that annoys me....